An obviousness rationale is required even when it is readily apparent that the prior art is physically capable of being modified to meet the limitations claimed. Here, for example, the fact that a prior art heat sink retaining device was physically capable of being rotated in a way similar to the device claimed was found to be insufficient to by itself establish obviousness of the claimed invention. “Even under a flexible and expansive approach to the obviousness inquiry, the raw ability to perform the [claimed] action without any reason to do so does not establish obviousness.” This would be a good case to cite in response to a naked assertion that one skilled in the art would have known how—rather than why—to modify the prior art to arrive at the claimed invention.

Background / Facts: The patent being asserted here is directed to heat sink dissipaters used to cool electronic components. The claims recite a retaining device that can rotate such that in a first orientation the device accommodates a CPU assembly of a certain thickness, and after rotation to a second orientation, the retaining device accommodates a CPU assembly of a different thickness while still engaging the dissipater’s top surface. Although it acknowledged that the prior art does not expressly refer to a second orientation, the district court nevertheless concluded that the claims were obvious because if the prior art device were to be rotated, its legs would fall within certain inter-fin gaps and thereby change the height of the device.

Issue(s): Whether it is necessary to establish a reason why one skilled in the art would modify the prior art in an obvious manner even when the prior art is demonstrably capable of such a modification.

Holding(s): Yes. “[E]ven to the extent that the [prior art] retaining device is physically capable of being rotated in a way similar to the device claimed in the [] patent, neither [the expert] nor the district court provided any basis for why one of skill in the art would rotate the [the prior art] retaining device in this manner. For example, nothing in [the expert] report or in the district court’s opinion suggests that such devices had been rotated in the past to enhance the usability of the retaining device. Even under a flexible and expansive approach to the obviousness inquiry, the raw ability to perform the rotation action without any reason to do so does not establish obviousness.”

Full Opinion